Commentaria in Summam contra Gentiles, Liber IV

Against the aforesaid position of Arius and Eunomius, St. Thomas argues by the authority of Scripture.¹

1. And first thus. According to the aforesaid position, angels and Christ would be called sons of God in the same sense: because to both, according to a certain likeness of the nature in which they were created, the name of filiation would belong. But this is clearly false: for in Heb. 1 it is said: To which of the angels said he at any time, Thou art my Son, this day have I begotten thee? — If it be said that that does not follow, because Christ is of a more excellent nature: — this does not stand in the way. Because different orders are also found among the angels; and yet the same character of filiation belongs to all.

Secondly. Christ would not be the only-begotten. The opposite of which is stated in John 1. — The consequence is proved. Because the name of filiation belongs also to all angels and saints by reason of divine creation.

Thirdly. If He were not called Son except by reason of creation, Christ could not truly be called a son. But the opposite of this is said in 1 John ult. Therefore etc. — The consequence is proved. Because the name of filiation properly and truly follows the generation of living things, in which the begotten proceeds from the substance of the begetter, which does not happen in creation.

Fourthly. Christ would not be true God: because nothing created can be called God except by a certain likeness to God. But this is false: as is clear in 1 John ult., This is the true God etc.

It must be observed concerning this reason and the preceding one, that true can be taken in two ways. In one way, as it is distinguished against false: just as a proposition by which it is signified as it is in reality is called true, while that by which it is signified not as it is in reality is called false. In another way, as it is distinguished against figuratively taken: in which way we say that a living animal is a true animal, but a painted one is not a true animal, but by a certain likeness. When therefore Christ is said to be the true Son of God, and true God, true is taken in the second way: and the sense is that He is Son of God and God according to the proper and essential meaning of these names.

II. Fifthly. In Rom. IX it is said: Who is over all things, God etc.; and in Titus II, Looking for the blessed hope etc.; and in Jer. XXIII, I will raise up to David a just branch, and it is added, and this is the name that they shall call him, The Lord our just one, where in Hebrew is found the tetragrammaton name, which is certain to be said of God alone. Therefore the Son of God is true God.

Sixthly. If Christ is the true Son, namely of God, it is necessary that He be true God: because that which is begotten by another cannot truly be called a son, even if it is born from the substance of the begetter, unless it proceeds into a like species of the begetter. But (supply) He is the true Son of God. Therefore etc. — Concerning the matter of this reason there will be a discussion below.²

Seventhly. Christ has in Himself the whole fullness of divine goodness: as is clear in Coloss. I ³. Therefore etc. — The consequence is clear. Because no creature receives the whole fullness of divine goodness.

Eighthly. The intellect of Christ does not fall short in knowledge from the divine intellect: since it is said in Coloss. II that in him are all the treasures etc. Therefore etc.

It must be observed that St. Thomas is not speaking here of the intellect of Christ's soul, which is a human intellect: for of this it is not true that it equals the knowledge of the divine intellect, as was shown above.⁴ But he speaks of His intellect absolutely: because namely there is in Christ some intellect not falling short in knowledge from the divine intellect: which, since such an intellect cannot be other than the divine intellect, it follows that in Christ there is a divine intellect, and consequently that He is God.

III. Ninthly. All things that the Father hath are the Son's: as is clear in John XVI and XVII. Therefore the essence and nature of the Father and the Son are the same. Therefore etc. — The first consequence is proved. Because whatever God has in Himself, is His essence.

Tenthly. The Son, before He emptied Himself taking the form of a servant, was in the form of God, as is said in Philip. II. But by the form of God is understood the divine nature, just as by the form of a servant is understood the human nature. Therefore etc.

Eleventhly. The Son is equal to the Father: since, as is clear from the narrative of John the Evangelist, John V, the Jews persecuted Christ because He said He was equal to God. But there is no doubt for a Christian that what Christ said about Himself is true: since the Apostle also says, Philip. II, that he thought it not robbery to be equal with the Father. Therefore etc. — The consequence is proved. Because nothing created can be equal to God.

It must be observed, however, that because this disputation is against a Christian who accepts the Gospel, St. Thomas therefore said, There is no doubt for a Christian that what Christ said about Himself is true. For an unbeliever could say that Christ sometimes vainly boasted of Himself: but for a Christian it is unlawful to say this.

IV. Twelfthly. Christ showed a perfect likeness of Himself to the Father also in living, John V: As the Father etc. Therefore etc. — The consequence is proved. Because by a perfect likeness no one's likeness to God is read of: as is clear in the Psalms when it is said, Who is like to God etc., and, O God, who shall be like to thee?

Thirteenthly. The Son represents the Father with respect to His essence: for in Coloss. I it is said that he is the image of the invisible God. And that He is a perfect image, representing the essence of God, through which it can be known of God what He is, is shown in Heb. I, when it is said: Being the brightness etc. Therefore etc. — The consequence is proved. Because no created substance represents God with respect to His substance.

2. Concerning this last statement a doubt arises. For every creature represents God: since it is His likeness. But it does not represent Him with respect to any accident of His: since in God there is no accident. Therefore it represents Him with respect to substance. Therefore it is false that no creature represents God with respect to His substance.

It is answered that for one thing to represent another with respect to substance can be understood in two ways: in one way, because it represents the very substance of the thing adequately and perfectly, according as it is signified through a definition; in another way, because it represents the substance of the thing inadequately and imperfectly, and not according to every mode of essential perfection. In this second way every creature represents God with respect to His substance, but not in the first way. But St. Thomas speaks of this mode. Which is evident because he is speaking of that representation of substance through which it can be known of a thing what it is. For that is a representation through a certain adequacy of the representing and the represented.

V. Fourteenthly. The Son of God is the universal cause of creatures: as is clear in John I, Prov. VIII, and Coloss. I. Therefore He is not of the genus of creatures. — The consequence is proved. Because nothing that is in some genus is the universal cause of those things that are in that genus, just as the universal cause of men is not some man: otherwise the same thing would be the cause of itself.

Fifteenthly. Jesus Christ, the Son of God, is the cause of the angels, producing them into being: as is clear from the Apostle saying: Whether thrones or dominations etc. Therefore etc. — The consequence is proved. Because angels cannot be made otherwise than through creation: and no created substance can create, as was shown in the Second, but God alone.

VI. Sixteenthly. The proper actions of God belong to the Son: such as to create, as has been shown; to uphold and preserve all things in being, and to purge sins, which is proper to God, as is clear in Coloss. I and Heb. I. Therefore etc. — The consequence is proved. Because the proper operation of any thing does not belong to anyone to whom the nature of that thing does not belong.

If it be said that the Son does these things, not by His own power, but by the power of the principal agent, whose instrument He is: — it is argued to the contrary. Because in John V, it is said that what things soever he doth, these also the Son doth in like manner. From which two things are held. One is that, just as the Father works per se and by His own power, so also the Son. — The other is that the power and ability of the Son and of the Father are the same. For since the same thing cannot be from two agents in the same way, but dissimilarly; or, if similarly, they must agree in one power; and the Son does all things whatsoever the Father does, and does them similarly, it is necessary that they agree in one power. But this is not as if from many imperfect powers found in them one perfect power were aggregated, just as from the powers of many pulling a ship one perfect power is made: since the power of God the Father is infinite, as was shown in the First. Therefore it is necessary that the power of the Father and the Son be numerically the same. — From which it is also further inferred that the essence of the Father and the Son must be numerically the same: since power follows the nature of a thing. — Which is also clear by this reason: because the divine nature cannot be multiplied, as was shown in the first book.

2. For the evidence of this matter, it must be considered that of one and the same effect there cannot be two total causes of the same genus and of the same order, as was shown in the preceding chapters.⁵ But there can well be several total causes of the same thing of different genera: for example, one in the genus of efficient cause, the other in the genus of final cause. Likewise there can be several of the same genus but of different orders: for example, in the genus of efficient cause one principal, the other instrumental. There can also be of the same thing several causes of the same order, but particular and imperfect, as it were integrating one total and perfect cause: as is the case with many pulling a ship.

When therefore it is said here that the same thing cannot be wrought by diverse agents in the same way, but dissimilarly etc., the sense is that the same thing cannot be produced by diverse total agents unless they exist in a diverse order, so namely that one is principal, while the other is instrumental: or, if similarly, that is according to the same order, something proceeds from several, they must agree in one power; either aggregated from many imperfect powers, because they are several partial imperfect agents together constituting one perfect agent; or numerically one simply existing in them,⁶ so that they are called not several agents substantively, but one, although they are several supposits acting by that one power. For there is a great difference between some things being several agents, and their being several acting supposits; for in the first, since the term agents is taken substantively, a plurality of power and of active form is signified; but in the second, since it is taken adjectively, a plurality only of the acting supposits is signified.

VII. Seventeenthly. Our beatitude is in the Son of God, namely objectively: as is clear in John XVII, and 1 John ult. — Our hope is also in Him: according to that of Isaiah, introduced by the Apostle, There shall be a root of Jesse etc. — And the honor of latria is to be rendered to Him. In the Psalm, And they shall adore him etc.; and in John V, That all men may honor the Son etc.; and again in the Psalm, Adore him all you his angels, which in Heb. I is introduced concerning Christ. Therefore etc. — The consequence is proved. Because those things belong to God alone, as was shown in the Third.

2. St. Thomas adds finally that toward showing this, those things are also valid which were adduced against Photinus to show that Christ is true God, not made, but begotten.

VIII. From these he infers as a corollary that only the faith of the Catholic Church, which posits the Son coeternal with the Father, and coequal, and true God of the same nature and essence with the Father, begotten, not created nor made, truly confesses generation in God, referring it to this, that the Son received the divine nature from the Father: whereas heretics refer it to an alien nature, Photinus indeed and Sabellius to the human, but Arius to a certain creature more noble than the rest of creatures.

IX. As to the second,⁷ he compares these opinions of the heretics with one another. And he says that as to generation, Arius differs from Sabellius and Photinus, because the former asserts that it was before the world, while the latter deny this. — But as to Christ Himself, they differ because Sabellius confesses Christ to be true and natural God, but not Photinus nor Arius. But Photinus differs from Arius, because Photinus says that He is a mere man, while Arius says that He is, as it were, commingled from a certain most excellent creature, divine namely in some way, and human. — But as to the person of the Son, Sabellius differs from the others, because they posit that the person of the Father and of the Son are different, which Sabellius denies.

The Catholic faith, however, walking the middle way, agrees with Arius and Photinus, positing that the person of the Father is one, that of the Son another, and that the Son is begotten, while the Father is unbegotten. But it agrees with Sabellius, saying that Christ is true and natural God of the same nature with the Father, although not of the same person.

From which St. Thomas infers that from this an indication of Catholic truth can be taken: since, as the Philosopher says, even false things bear witness to the true, while false things also stand at variance with one another.

It must be observed that false things are said to bear witness to the true sometimes, not indeed on that part by which they are false, but insofar as they contain something of truth.